Chain grate.



C. G. M. BENNETT & S. H. SMITH.

v CHAIN GRATE.

APPLICATION FILED MR.25. I9I3.

1 ,206, 1 97. Patented Nov. 28, 1916.

2 SHEETS-SHEET I.

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C. G. M. BENNETT & S. H. SMITH.

CHAIN GRATE.

APPLICATION FILED MAn.25. |913.

Patented Nov. 28,I 1916.

2 SHEETS-SHEET 2.

@E gw@ ntofc UNITED STATE PATENT` FFICE.

CYRIL GEORGE MANCHA BENNETT, OF LONDON, AND SYDNEY HERBERT SMITH, OF WEST- EALING, ENGLAND, ASSIGNORS TO THE .BABCOCK @c WILCOX COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY. l

CHAIN GEATE.

Specification of Letters Patent.

Patented Nov. 2s, 1916.

Application led March 25, 1 913. Serial No. 756,674.

invented certain new and useful Improve? ments in Chain Grates, of which the following is a specification.

vOur invention relates to improvements in revolving chain grates' very generally used in the furnaces of steam boilers, refuse destructors and for like purposes, and more particularly to that class of chain grate which is formed of a number of transverse series of links or rebars which are pivot# ally connected with their transverse supports at one end only and are so constructed that on the return journey toward the front of the furnace around the carriage on which they are mounted they turn like flap valves, thus ,dropping any collection of ashes or partially consumed fuel which may be dropped from the top portion of the chain on to the bottom portlon.` Owing to this.,

action of the firebars which form the grate the Stoker is self-cleaning while the frebars are kept cool and an -easypath is provided for the entrance of the` air to the' top portion of the chain which Iis moving toward the back of the furnace. i

From experience it is found that the life of the top part of a irebar, which carries the fuel to be burnt and therefore receives the eatest heat, is considerably less than the rame andhinge or hinges of said {irebar.

The irebars of our invention are conveniently built up from a broad light framework which is pivotally mounted at one end on the transverse members or supports of `the chain. This framework is provided with a separable top part which may be provided with air slots. This -top part effectively protects the frame on which it is mounted while it can be changed or renewed by hand without disturbing either the frame or the transverse member of the chain on which said frame is pivoted. Owing tothe breadth `of the framework of the frebars as compared with the irebars now usually employed in ,chain grates we reduce the number of joints in the chain and consequently we materially reduce the yfriction in working and at the same time lbring about a'large reduction ofthe riddling of small coal between said rebars.

Our invention is illustrated by way of'exvample in the accompanying drawings in whch- Figure 1 isa plan view of a flap firebar;

Fig. 2, a side view of Fig. l; Fig. 3 a sect1on on the line A-B of Fig. 1; Fig. 4 a

:detail plan view of the underside of a separable top; Fig. 5 a side view of Fig. 4; Fig. 6 a bottom plan view of the, frame; and Fig.

. 7 is a side elevation, broken away and partly in section, of a complete chain grate illustrating a method of utilizing the invention. The broad irebars of our invention are built up from a light framework l illustrated more particularly in Fig. 6 which is adapted to be pivotally mounted at one end on the transverse members or supports 2 of the chain. This framework 1 is provided with a separable top part 3 adapted to carry the fuel to be burnt. As shown the said toppart 3 is preferably provided with air slots 4 which may vary in size and number thus allowing of a chain grate which is tted with such flap flrebars being partially or wholly refitted with irebars having more or less air supply without disturb- Y ing the chain or the transverse members on which the irebars 'are mounted. The said top part 3 effectively protects the frame 1 on which it is mounted while it can be removed and renewed by hand without disturbing either the frame or the transverse member 2 ofthechain on which said frame 1 is pivoted. In order thatsaid.l top part can'be easily removed we may form at the inner or hinge end of the frame 1 an undercut 5 as shownmore particularly in Fig. 3 while the adjacent edge 6 of the removable top portion 3 is tapered outward so as to project into said under-cut edge when said top portion 'is in position in its frame as shown -in Fig. 3. This under-cut edge 5 is adapted to retain said top portion in position when the firebars are passing into the position of use over the front end of the carriage on which the chain is mounted.

The said top portion 3 may be provided on its underside near the opposite end to its lip 6 with a lug 7 adapted to lie when in position against the cross bar 8 of said frame 1. The said lug 7 and cross bar 8 are provided with corresponding centrally placed holes adapted to receive a suitable pinA such as for instancea split pin 9 illustrated in Fig. 3. Instead of a pin such as illustrated, or bolt or the like we may attach said top part to its frame by bayonet connections which will normally hold said top part in position, so that it cannot fall olf its frame in any position on the carriage on which the chain is mounted; such bayonet connections may comprise bayonet recesses on the inner surface of each side of the frame, adapted to receive engaging members projecting laterally from the under surface of the top portion.

One method of utilizing our invention is illustrated in Fig. 7, which shows a complete chain grate. The Hap ire-bars are mounted on thel transverse bars 2 of the chain 10, which is moved in the direction of the arrow by the sprocket 11. The chain 10 is supported by upper guide rollers 12 and lower guide rollers 13, journaled in the movable carriage 14. Upon the return movement of the links or fire-bars, toward the front of the carriage, they turn like Hap valves at points intermediate the rollers 13, thus dumping an ar'tially consumed fuel or ashes which may have dropped from the top portion to the lower portion of the chain.

.What we claim and' desire to secure by Letters Patent of the United States, is

1. A a firebar for chain grates comprising a fiame having means for pivotally connecting one end only to a grate chain, a removable top, said frame having an undercut portion at the hinged end thereof, there being a projection on the removable top adapted to be seated in the undercutl portion of the frame, and means for` securing the other end of the top to the frame, substantially as described.

2. A chain grate Stoker comprising a plurality of chains, grate bar supporting members connected to said chains, a series of bars pivotally connected each at one end only to said supporting members, each of said grate bars comprising a frame and ak removable topthe frame having an undercut portion and the top having at one end a projection adapted to be seated in the undercut portion, and means for securing the other end of the top to the frame, the arrangement being such' that the top is adapte'd to fall downwardly from the frame when said securing means is inactive and the grate bar is vertically suspended from its supporting member, substantially as described.

In testimony whereof we have hereunto signed our names in the presence of two sub.

scribing witnesses.

CYRIL GEORGE MANCHA BENNETT. SYDNEY HERBERT SMITH. Witnesses:

S. J. WESTON, H. P. SMITH. 

